title: Metabolomic profiling of asthma: diagnostic utility of urine nuclear magnetic resonance spectroscopy.
abstract: BACKGROUND
  The ability to diagnose and monitor asthma on the basis of noninvasive measurements of airway cellular dysfunction is difficult in the typical clinical setting.
  
  
  OBJECTIVE
  Metabolomics is the study of molecules created by cellular metabolic pathways. We hypothesized that the metabolic activity of children with asthma would differ from healthy children without asthma. Furthermore, children having an asthma exacerbation would be different compared with children with stable asthma in outpatient clinics. Finally, we hypothesized that (1)H-nuclear magnetic resonance (NMR) would measure such differences using urine samples, one of the least invasive forms of biofluid sampling.
  
  
  METHODS
  Children (135 total, ages 4-16 years) were enrolled, having met the criteria of healthy controls (C), stable asthma in the outpatient clinic (AO), or unstable asthma in the emergency department (AED). Partial least squares discriminant analysis was performed on the NMR data to create models of separation (70 metabolites were measured/urine sample). Some NMR data were withheld from modeling to be run blindly to determine possible diagnostic accuracy.
  
  
  RESULTS
  On the basis of the model of AO versus C, 31 of 33 AO samples were correctly diagnosed with asthma (94% accuracy). Only 1 of 20 C samples was incorrectly labeled as asthma (5% misclassification). On the basis of the AO versus AED model, 31 of the 33 AO samples were correctly diagnosed as outpatient asthma (94% accurate).
  
  
  CONCLUSIONS
  This is the first report suggesting that (1)H-NMR analysis of human urine samples has the potential to be a useful clinical tool for physicians treating asthma.
authors.affiliation: Department of Pediatrics, University of Alberta, Magnetic Resonance Diagnostics Centre, Edmonton, Alberta, Canada.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Saude
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Skappak
authors.forename: Shana
authors.initials: S
authors.lastname: Regush
authors.forename: Kim
authors.initials: K
authors.lastname: Cook
authors.forename: Amos
authors.initials: A
authors.lastname: Ben-Zvi
authors.forename: Allan
authors.initials: A
authors.lastname: Becker
authors.forename: Redwan
authors.initials: R
authors.lastname: Moqbel
authors.forename: Brian D
authors.initials: BD
authors.lastname: Sykes
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
authors.forename: Darryl J
authors.initials: DJ
authors.lastname: Adamko
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis / Q000652:urine*; D015415:Biomarkers / Q000652:urine*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D055432:Metabolomics; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers